One of the many significant challenges mankind faces as we look to expand our footprint in outer space is the hostile space radiation environment. Not unlike many other mission parameters, the doses imparted to astronauts from extraterrestrial radiation could potentially be a limiting factor when considering the longevity of any manned mission. Thus, a detailed knowledge of dose and dose distribution with regard to the tissue-dependent International Commission on Radiological Protection limits would be beneficial to ensure crew safety.
In this work, the Standalone Package for Enhanced Estimation of Dose Distribution (SPEEDD) is developed in order to provide a method of calculating an accurate three-dimensional dose distribution for a space crew. The current version presents a prototype of the software package. The three sources considered when operating in space are solar particle events, galactic cosmic radiation, and trapped radiation belts. In this technical note, trapped radiation will not be discussed in great detail. SPEEDD combines high-fidelity human phantoms with depth-dose tables in order to rapidly calculate whole-body dose as well as individual organ doses. The anatomical phantoms used in SPEEDD are the RPI Adult Male and the RPI Adult Female. They were developed by the Rensselaer Radiation Measurement & Dosimetry Group and are cubically voxelized with a resolution of 2.7 and 2.5 mm, respectively. Generated using the High Energy Transport Code–Human Exploration and Development in Space (HETC-HEDS) Monte Carlo radiation transport code, the depth-dose tables consist of all ions from hydrogen to iron characterized at 18 energy bins ranging from 20 AMeV to 3 AGeV. SPEEDD was written in the Python™ scripting language and is designed to be easily installed or added to larger software packages.